Первое - ffmpeg -i 473975_1.mp4 -vcodec libwebp -filter:v fps=fps=25 -lossless 0 -compression_level 3 -q:v 70 -loop 1 -preset picture -an -vsync 0 -s 100:100 $(uuidgen).webp

Второе - ffmpeg -i 473975_1.mp4 -vcodec libwebp -filter:v fps=fps=25 -lossless 0 -compression_level 3 -q:v 70 -loop 1 -preset picture -an -vsync 0 -s 1500:1500 $(uuidgen).webp